Certain machines such as motor graders have a natural frequency that may negatively affect their operation due to resonance at such natural frequency. The natural frequency of a motor grader is a function of numerous physical characteristics of the machine such as its weight distribution, the distance between the rear wheels and the moldboard, and the tire characteristics. In addition, the operating conditions encountered by the motor grader may also affect the natural frequency. Excitation at the natural frequency may result in harmonic vibrations within the motor grader commonly referred to as “bounce.”
Harmonic vibrations or bounce typically occur when the motor grader is operated within a particular range of speeds and with a light load on the blade or moldboard. The movement caused by the bouncing condition may interrupt the contact between a work surface and the moldboard which may result in an uneven finish or scallop on the work surface. Such an uneven finish may require reworking of the work surface or the application of additional material for proper finishing.
Motor graders may experience three different types of harmonic vibrations or bounce: pitching, side-to-side or “duck-walk,” and vertical vibrations or bounce. Each of these types of harmonic vibrations or bounce conditions may negatively impact a grading operation. Harmonic vertical movement or bounce generally occurs at a frequency between 1.5 and 3 Hz.
U.S. Patent Publication No. 2010/0051298 A1 discloses a system for detecting and dissipating hydraulic spikes in pressure caused when implements of a machine bounce. The pressure spikes are dissipated by generating random or canceling pulses within the hydraulic system.
The foregoing background discussion is intended solely to aid the reader. It is not intended to limit the innovations described herein, nor to limit or expand the prior art discussed. Thus, the foregoing discussion should not be taken to indicate that any particular element of a prior system is unsuitable for use with the innovations described herein, nor is it intended to indicate that any element is essential in implementing the innovations described herein. The implementations and application of the innovations described herein are defined by the appended claims.